JEE Main 2025 — Chemical Kinetics Question with Solution

$\mathrm{A}\to \mathrm{B}$ The molecule A changes into its isomeric form B by following a first order kinetics at a temperature of 1000 K . If the energy barrier with respect to reactant energy for such isomeric transformation is $191.48\mathrm{kJ}{\mathrm{mol}}^{-1}$ and the frequency factor is $10^{20}$, the time required for $50\%$ molecules of A to become $B$ is _________ picoseconds (nearest integer). $\left[\mathrm{R}=8.314\mathrm{J}{\mathrm{K}}^{-1}{\mathrm{mol}}^{-1}\right]$